Dataset DOI: 10.5061/dryad.bcc2fqzs5

Description of the data and file structure

This dataset contains all the necessary data for reproducing the results of the research, as described in the manuscript with the name:

'Feeding performance, kinematics and skills change with age in a granivorous songbird'

The data includes raw measurements obtained from both manual video analysis and automated beak tip tracking using DeepLabCut software, as well as the code for statistical analysis.

In summary, this dataset includes:

• 10 .csv files of raw measurements, each pertaining to a specific metric (or group of metrics), and 1 'master' .csv file ('age_summary') combining the data of the other 10 files.
• an R-file with the code for statistical analyses and associated .txt files (see below; code/software).

Files and variables

General terminology (this is a list of terms that is used across most of the files):

• bird: identification number of the individual
• sex: sex of the individual (M = male, F = female)
• birth_year: Year of birth of the individual
• age_group: indicates whether the individual is a juvenile (young) or adult (adult) at the start of the experiments.
• weight: Body mass of the individual prior to the experiment (in g)
• session: A number from 1 to 4 indicating the recording session of the respective individual (individuals were recorded 4 times, every 6 months over the course of 2 years).
• NA: no data available because the individual refused to feed on the respective seed type or had died prior to the respective experiment.

age_summary.csv:

this is the 'master' file, which contains average values of all variables per individual of both seed types. This file was used for all statistical analyses.

Terminology:

• rec_date: date of the day the experiment was conducted on.
• age_month: age of the individual at the time of the experiment in number of months.
• seed: seed type the individual fed on (canseed = canary seed, hemp = hemp seed)
• picking_duration: Average duration of the picking and head righting phase (in s)
• cracking_duration: Average duration of the positioning and cracking phase (in s)
• swallowing_duration: Average duration of the husk removal and swallowing phase (in s)
• total_duration: Average duration of the entire feeding act (in s)
• success_rate: Proportion of seed husking attempts that are successful (in %)
• position: Average head position during seed cracking (number between 0 and 1)
• splitting_seed: Proportion of successful seed husking attempts where the seed is being split in two halves (in %)
• max_gape: Average maximum gape size (in mm)
• min_gape: Average minimum gape size (in mm)
• opening_velocity: Average maximum beak opening velocity (in mm/s)
• closing_velocity: Average maximum beak closing velocity (in mm/s)
• opening_acceleration: Average maximum beak opening acceleration (in mm/s²)
• closing_acceleration: Average maximum beak closing acceleration (in mm/s²)
• frequency: Average opening-closing frequency of the beak (in Hz)
• amplitude: Average beak amplitude during opening-closing (in mm)

cracking_mode_canary_age.csv & cracking_mode_hemp_age.csv:

these files list out the cracking mode during successful seed husking attempts in chronological order per individual, for canary seed and hemp seed respectively.

Terminology:

• S = seed splitting
• C = seed crushing
• splitting: Proportion of successful seed husking attempts where the seed is being split in two halves (in %)
• crushing: Proportion of successful seed husking attempts where the seed is being crushed in irregular pieces (in %)

head_position_canary_age.csv & head_position_hemp_age.csv:

these files list out the head position during successful seed husking attempts in chronological order per individual, for canary seed and hemp seed respectively.

Terminology:

• L = low head position
• M = medium head position
• H = high head position
• position: Average head position during seed cracking (number between 0 and 1)

kinematics_canary_age.csv & kinematics_hemp_age.csv:

these files contain kinematic variables extracted from 5 tracked feeding trials per individual, for canary seed and hemp seed respectively.

• trial: number of the respective feeding trial
• Frame range start: Starting frame of fragment of interest
• Frame range end: Ending frame of fragment of interest
• cut-off frequency: cut-off frequency for filtering (in Hz)
• frequency fragment start time: Starting time for frequency calculation (in s), relative to fragment of interest
• frequency fragment end time: Ending time for frequency calculation (in s), relative to fragment of interest
• number of cycles: Number of opening-closing cycles from which frequency and amplitude are calculated
• max gape: maximum gape size (in mm)
• min gape: minimum gape size (in mm)
• max opening velocity: Maximum beak opening velocity (in mm/s)
• max closing velocity: Maximum beak clsoing velocity (in mm/s)
• max opening acceleration: Maximum beak opening acceleration (in mm/s²)
• max closing acceleration: Maximum beak closing acceleration (in mm/s²)
• mean fragment frequency: average opening-closing frequency of fragment of interest (in Hz)
• mean fragment amplitude: average beak amplitude during opening-closing of fragment of interest (in mm)

phase_duration_canary_age.csv & phase_duration_hemp_age.csv:

these files contain phase durations of 10 feeding trials per individual, for canary seed and hemp seed respectively.

• trial: number of the respective feeding trial
• picking: Duration of seed picking and head righting phase (in number of frames)
• cracking: Duration of positioning and cracking phase (in number of frames)
• swallowing: Duration of husk removal and swallowing phase (in number of frames)
• total: Duration of the entire feeding act (in number of frames)

success_rate_canary_age.csv & success_rate_hemp_age.csv:

these files list out whether seed husking attempts are successful or not in chronological order per individual, for canary seed and hemp seed respectively.

• V = success
• X = failure
• V_tot: Number of successful attempts
• X_tot: Number of failed attempts
• Rate: Proportion of seed husking attempts that are successful (in %)

age.R:

R-file detailing the mixed linear modelling and construction of graphs used in the manuscript.

age_cans.txt:

Text file containing the data during feeding on canary seed from age_summary.csv, ready to use in the R-script for the statistical analyses.

age_hemp.txt:

Text file containing the data during feeding on hemp seed from age_summary.csv, ready to use in the R-script for the statistical analyses.

Code/software

All statistical analyses were conducted in R (version 4.3.3).

This dataset includes an R-file with the full script for the statistical analyses and generation of graphs. Additionally, .txt-files of the relevant data are included in this dataset, ready-to-use in the R-file.

The required packages are: 'lme4' and 'lmerTest' for linear mixed modelling, and 'ggplot2' for graph generation.

Access information

All data is extracted from high-speed video recordings which are not publicly available due to their file size (+- 180 TB in total). These videos can be accessed upon request by contacting the corresponding author.